Problem: $\left[\begin{array} {ccc} 3& 3\\ -6& -6 \end{array}\right]$ What are the dimensions of the matrix?
Answer: The first dimension is the number of rows in the matrix. There are $2$ rows. The second dimension is the number of columns in the matrix. There are $2$ columns. In conclusion, the dimensions of the matrix are $2\times 2$.